Tag: supercritical co2 cycles

Our next webinar is on October 8th! Join us as we discuss Design of Waste Heat Recovery Systems Based on Supercritical ORC for Powerful Engines.

Waste heat recovery is a hot topic (pun intended) that SoftInWay embraced rapidly. Numerous projects have been successfully performed on both the thermodynamic and the turbomachinery components levels.

In this webinar, we will discuss the case of a powerful ICE that can now benefit from a 20% boost in power due to waste heat recovery using a supercritical organic Rankine cycle (SORC). Different configurations, levels of complexity and parameters are studied and compared for the thermodynamic cycle as well as different fluid. Moreover, to show you that SORC is the way to go the results obtained are compared to what would be obtained with a different type of WHR system; double-pressure water steam cycle.

The session will include:

Introduction to the powerful ICE considered and its waste heat sources

Working fluid and parameters selection for the waste heat recovery system (WHRS)

Comparison of different configurations of WHRS SORC

Preliminary design of the turbine(s)

Who should attend?​

Engineers actively contributing to making their processes more efficient.

Engineers working in the mechanical, aerospace, automotive, marine, power generation industries who want to optimize their process equipment by utilizing untapped heat.

Engineering students looking for a comprehensive and state-of-the-art case study to optimize existing equipment allowing them to widen and deepen their understanding of waste heat recovery to meet the requirements of future employers.

Gas turbines are continuing their trend in becoming more efficient with each generation. However, the rate at which their efficiency increases is not significant enough to match more and more constraining environmental goals and regulations. New technologies like combined cycles therefore need to be used to increase cycle-specific power (more power produced without burning additional fuel).

The first generation of combined cycles featured a bottoming steam cycle that uses the heat from the gas turbine exhausts to boil off water in order to power a turbine and generate power. This traditional approach has been around since about 1970 and nowadays allows obtaining an additional 20% in cycle thermal efficiency (40% in simple gas turbine cycle configuration vs. 60% as a combined gas-steam cycle).

Figure 1: General efficiency increases over time for simple and combined cycle gas turbinesFigure 2: Example of a simple, recuperated Brayton, supercritical CO2 cycle that uses the exhaust flow of a gas turbine to heat its working fluid

While this traditional approach is definitely effective, it does have some drawbacks; the equipment usually takes a significant amount of 3D space, there is always the risk of corrosion and substantial structural damage when working with 2-phase fluids, and so on. This, therefore, allows for different technologies to emerge, like supercritical CO2 cycles.

A supercritical fluid is a fluid that is used above its critical pressure and temperature and therefore behaves as neither a liquid nor a gas but as a different state (high density vs gas, absence of surface tensions, etc.). As a working fluid, supercritical CO2 has numerous advantages over some other fluids, including a high safety usage, non-flammability/toxicity, high density, inexpensiveness and absence of 2-phase fluid.

Figure 3: Example of difference in power density between supercritical carbon dioxide (left) and steam (right) for a 10 MW power turbine

Moreover, steam turbines are usually difficultly scalable to small capacities which mean that they are mostly used in a bottoming cycle configuration for high power gas turbines. On the other hand supercritical CO2 (Rankine) cycles can be used for smaller machines as well as the bigger units while featuring an efficiency comparable to the one of a typical Rankine cycle and estimated lower installation, operation and maintenance costs.

The paper I presented at the ASME Power & Energy 2015 compares different configurations of SCO2 bottoming cycles for an arbitrary case for different boundary conditions before applying the selected cycle to a wide range of existing gas turbine units. This allowed determining how much additional power could be generated without needing to burn additional fuel and the results were far from insignificant! For the machines studied the potential for power increase ranges from 15% to 40% of the gas turbine unit power. Want to know how much more power you can get with your existing machines? Contact us to get a quote for a feasibility study before designing the waste heat recovery system yourself or with our help.

This week’s TBT webinar, Design of Impulse and Reaction Turbines Webinar #2: Applications for Supercritical CO2 Cycle, discusses important considerations for using high-density working fluids with small turbine sizes. Structural constraints and performance are considered and the full design process is demonstrated.

Do you want to enhance your thermal or nuclear electricity generation project with advanced power conversion technologies?

Are you interested in expanding into the Supercritical CO2 Cycle business?

If you answered ‘yes’ to any of these questions, watch “Supercritical CO2 Cycle – Advanced Power Conversion Technology,” which we recorded and put in our resource center! Learn more about technological advantages and most effective solutions in S-CO2 Cycle Turbine design!

The supercritical CO2 power cycle is one of the most promising power technologies. It is not by chance though, because carbon dioxide (CO2) has a unique combination of attributes, such as a low critical temperature, an environmentally natural origin, a high standard of safety and a low cost. Carbon dioxide is also thoroughly studied, therefore there is sufficient information surrounding it. But on the other hand, the supercritical CO2 cycle has a high energy conversion factor, such as high thermal efficiency.Continue reading “Designing Supercritical CO2 Power Plants”→